JB/T 2984.2-1999 This standard is a revision of ZB J85 004.1-87 "Bolts for drive gear segments of crawler bulldozers". During the revision, only editorial changes were made according to relevant regulations, and the main technical content remained basically unchanged. This standard specifies the type and size, requirements, test methods, inspection rules, marking methods, packaging, transportation and storage of bolts for drive gear segments of crawler bulldozers. This standard is applicable to bolts for drive gear segments of crawler bulldozers, bulldozers, loaders and pipelayers. This standard was first issued on April 4, 1987. JB/T 2984.2-1999 Bolts for drive gear segments of crawler bulldozers JB/T2984.2-1999 Standard download decompression password: www.bzxz.net

ICS53.100
Machinery Industry Standard of the People's Republic of China
JB/T2984.2-—1999
Crawler bulldozer
Bolts for drive sprocket segment Issued on August 6, 1999
National Bureau of Machinery Industry
Implemented on January 1, 2000
JB/T2984.2—1999
This standard is a revision of ZBJ85004.187 "Bolts for drive sprocket segment of crawler bulldozer". During the revision, the original standard was edited, and the main technical content remained basically unchanged. This standard replaces ZBJ85004.1—87 from the date of implementation. This standard is proposed and managed by the Technical Committee for Standardization of Construction Machinery. This standard was drafted by: Tianjin Engineering Machinery Research Institute, Hubei Yangxin High Strength Bolt Factory, Ningbo Zhenhai High Strength Fasteners Industrial Company, Changshu Yinghu International Standard Fasteners Co., Ltd. The main drafters of this standard are: Li Mingxiang, Deng Changming, Zhang Xiankang, Zhao Qingyun. This standard was first issued on April 4, 1987 and revised for the first time in 1999. 1 Scope
Machinery Industry Standard of the People's Republic of China
Crawler bulldozer-
Bolts for drive sprocket segment
Crawler bulldozer-
Bolts for drive sprocket segmentJB/T2984.2—1999
Replaces ZBJ85004.1-87www.bzxz.net
This standard specifies the type and size, requirements, test methods, inspection rules, marking methods, packaging, transportation and storage of bolts for drive sprocket segments of crawler bulldozers (hereinafter referred to as bolts). This standard applies to bolts for drive gear segments of crawler bulldozers, bulldozers, loaders, and pipelayers. 2 Reference standards
The provisions contained in the following standards constitute the provisions of this standard through reference in this standard. When this standard is published, the versions shown are valid. All standards are subject to revision. Parties using this standard should explore the possibility of using the latest versions of the following standards GB/T90—1985
GB/T193—1981
GB/T1971981
GB/T3077—1999
GB/T3098.1—1982
GB/T5779.11986
3 Types and sizes
Fastener acceptance inspection, marking and packaging
Ordinary thread diameter and pitch series (diameter 1~600mm) Ordinary thread tolerance and fit (diameter 1-355mm) Alloy structural steel
Mechanical properties of fasteners Bolts, screws and studs Surface defects of fasteners General requirements for bolts, screws and studs
The type and size of bolts shall comply with the provisions of Figure 1 and Table 1, and the quality shall comply with the provisions of Table 2. A
Approved by the State Machinery Industry Bureau on 1999-08-06+0
C,x45\ka
C, 45\k3
Implementation of 2000-01-01
Basic size
Limit deviation
Basic size
Limit deviation
Basic size
Limit deviation
JB/T2984.2—1999
Mass of every 1000 bolts
Marking example:
JB/T2984.2—1999
Fine pitch ordinary thread, diameter 22mm, pitch 1.5mm, thread accuracy 6g, length 60mm tooth block bolt, marked as: Bolt M22X1.5x60-6gJB/T2984.219994 requirements
Bolts shall be made of 35CiMoA material specified in GB/T3077 (other materials whose technical properties meet the requirements of this standard are allowed to be used).
The mechanical properties of the bolts shall comply with the provisions of Table 3. Table 3
35CrMbA
Tensile strength G
≥1098
The tightening torque of the bolts shall comply with the requirements of Table 4d
Assembly torque
Assembly load
461-559
Yield strength 6,
883-1078
Impact value ak
1078-1275
2550-3138
The thread shall comply with the fine pitch ordinary thread specified in GB/T193, the thread tolerance zone shall comply with the 6g grade in GB/T197, and the root shape of the external thread shall comply with Chapter 3 of GB/T1971981. 4.5
The surface roughness R value of the external thread working surface is 3.2um, and the surface roughness of the major diameter is not specified. Bolts should not have flash, scale, cracks or other defects that affect actual use. The straightness of the bolt axis should be less than (0.3/100)1. The bolt surface should be oxidized and coated with anti-rust oil. Test method
Finished product tensile test
The finished product tensile test of bolts shall be carried out in accordance with 8.2 of GB/T3098.11982. The tensile load shall comply with the provisions of Table 5. Table 5
Tensile load
Bolt wedge load test
JB/T2984.2—1999
The finished product wedge load test of bolts shall be carried out in accordance with 8.5 of GB/T3098.1—1982, and the tensile load shall comply with the provisions of Table 5. 5.3 Guaranteed load test
The guaranteed load test of bolts shall be carried out in accordance with the provisions of 8.4 of GB/T3098.1-1982, and the guaranteed load shall comply with the provisions of 10.9 level in GB/T3098.1.
5.4 Impact test
The impact test of bolts shall comply with the provisions of 8.6 of GB/T3098.1-1982. 5.5 Hardness test
The hardness test of bolts shall be carried out in accordance with the provisions of 8.3 of GB/T3098.1-1982. 5.6 Decarburization test
The decarburization test shall be carried out in accordance with the decarburization requirements of 10.9 level in GB/T3098.1 and the test method specified in 8.8 of GB/T3098.1-1982. 5.7 Flaw detection test
The finished product shall be subjected to magnetic particle inspection and demagnetization treatment, and no fire cracks are allowed. The remaining micro cracks shall be in accordance with the provisions of GB/T57791. 6 Inspection rules
6.1 The bolts shall be inspected by the inspection department of the manufacturer according to the product drawings and this standard, and the bolts shall have a factory certificate. 6.2 The bolts produced in batches shall be sampled before leaving the factory. The sampling method shall be in accordance with the provisions of GB/T90, n-80 pieces, and the qualified quality level (AQL) and qualified judgment number (Ac) shall be determined according to the importance of the inspection items. 7 Marking method
Print the mark and trademark on the top surface of the bolt head, marked as X× (indicating the strength level of the bolt), and the mark and trademark shall be clear (see Figure 2). xx
8 Packaging, transportation and storage
8.1 Before packaging the bolts, dirt and metal chips shall be removed, the surface shall be coated with rust inhibitor, and the bolts shall be packed in wooden boxes or calcium plastic boxes lined with moisture-proof paper, and ensure that the parts will not be damaged during normal transportation. The weight of a single box shall not exceed 30kg. 8.2 The packing box should be accompanied by a certificate signed by the manufacturer’s inspector, and the product name, model and quantity should be clearly stated. 8.3 The packing box should be marked with: a) Manufacturer’s name: b) Product name and model: e) Product specifications or markings d) Number of pieces and net weight; e) Manufacturing (ex-factory) date. 8.4 The bolts should be placed in a ventilated and dry warehouse after packing. Under normal storage conditions, they will not rust within one year from the date of leaving the factory. 4
Republic of China
Mechanical Industry Standard
Bolts for drive wheel gear blocks of crawler bulldozers JB/T2984.2-1999
Published and distributed by the Mechanical Science Research Institute
Printed by the Mechanical Science Research Institute
(Beijing Capital No. 2, Ti-Nan Road: Postal Code 100044)*
Format 880×12301/16 Printing Sheet 1/2
Word Count 10000
First Edition March 2000 First Printing March 2000 Print Quantity 1-500 Pricing RMB 500
No. 99-1278.1
Mechanical Industry Standard Service Network: http:/AwwwJB.ac.cn68
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